Periodic mescury switch mechanism



July 8, 1952 I ER 2,602,865

PERIODIC MERCURY SWITCH MECHANISM Filed Dec. 9, 1949 Inventor Mar/0n f. Maurer Patented July 8, 1952 UNITED STATES PATENT OFFICE PERIODIC MERCURY SWITCH MECHANISM Marion F. Maurer, Springfield, Ohio Application December 9, 1949, Serial No. 132,014

' 6 Claims. (01. 200-33) My invention relates to improvements in periodic mercury switch mechanisms for controlling, especially, although not necessarily, operation of a motor drive in timed relation to rotation of another mechanism.

The primary object of my invention is to provide for accurately timing a motor drive for intermittent cyclic operation in timed relation to cyclic operation of another mechanism, and by quick acting mechanical means of simple form and inexpensive construction for opening and closing a mercury control switch for the motor.

Another object is to provide mechanical means for obviating arcing in the mercury tube of the mercury switch by vibration during closing of the switch.

Still another object is to provide periodic mercury switch mechanism which will withstand prolonged use, is easy to service, and proof against incorrect operation.

Other and subordinate objects, within the purview of my invention, together with the precise nature of my improvements, will be readily understood when the succeeding description and claims are read with reference to the drawing accompanying and forming part of this specification.

In said drawing:

Figure 1 is a view in front elevation of my invention with the mercury switch open;

Figure 2 is a view in horizontal section taken on the line 2-2 of Figure 1 and illustrating on a larger scale the position of the switch controlling member, disk cam and rocker arm in Figure 1;

Figure 3 is a view in front elevation illustrating the mercury switch closed;

Figure 4 is a view in. horizontal section taken on the line 4-4 of Figure 3 and illustrating on a larger scale the position of the switch controlling member, the disk cam and rocker arm in Figure 3;

Figure 5 is a view in front elevation illustrating the mercury switch closed and the tappet pin in position to rock the mercury switch into open position;

Figure 6 is a view in horizontal section taken on a line 6--t of Figure 5 and illustrating on a larger scale the position of the switch control member, the disk cam, and the rocker arm in Figure 5;

Figure '7 is a fragmentary view in horizontal section taken on the line l'! of Figure 5 and drawn to a larger scale;

Figure 8 is a fragmentary view in perspective illustrating the manner in which the flange of the switch controlling member flexes to permit the rocker arm to move out of the member over the flange in wiping engagement therewith;

Figure 9 is a view in transverse section taken on the line 99 of Figure 2.

Describing my invention in detail, with reference to the drawing by numerals, in the exemplifying practice illustrated, the invention is concerned with a motor drive, designated generally by the numeral I, and comprising an electric motor 2 for operating a horizontal power transmitting shaft 3 by speed reducing gearing including a Worm 4 on the armature shaft of the motor 2 driving a worm gear 6 fast on a worm shaft 1, and a small spur gear 8 on the worm shaft 1 meshing with a larger spur gear 9 fast on the power transmitting shaft 3, all of which may be suitably mounted on a supporting structure such as that designated by the numeral iii.

The described motor drive I is timed with relation to a conventional water meter l l beneath the spur gear 9 interposed in the water supply line !2 and having a shaft l3 extending upwardly therefrom below the spur gear e and fixed in relation to said gear by being journaled in a bearing l4 on the support ID. The shaft 13 rotates at a slower speed than the power transmitting shaft 3.

An annular, dished switch controlling member with a flexible, resilient, circumferential flange I6 is fitted coaxially on the upper end of the shaft l3 below the spur gear 9 contiguous thereto, in horizontal position and rests upon a collar ll surrounding said shaft IS. The flange 55 of the switch controlling member (5 is provided with a circumferentially extending notch l8 of a length suitable for a purpose presently seen.

A disk cam l9, relatively smaller in diameter than the switch controlling member is is fitted on the squared upper end 20 of the shaft [-3 and in said controlling member l5, by a nut 21 on said end 29, and with collars 2| on said shaft spacing said disked cam [9 above the bottom of the switch controlling member is substantially level with the rim of said flange IS. A pin 22 on the disk cam l9 extending through a bottom aperture 23 in the switchcontrolling member I5 couples said cam to said controlling member in driving relation thereto. The disk cam L) fixed on the shaft 13 eccentrically thereof and of said controlling member 15 and extends out of the notch l8 so that its edge forms a continuation of one end of the notch I8 and is spaced from the other end of said notch to provide a gap 24 between said other end and said disk.

A mercury switch 25 is mounted on the support I9 alongside the spur gear 9 to rock vertically in opposite directions into open and closed positions, respectively. The mercury switch comprises the usual mercury tube 26 which, in this instance, is fixed horizontally, by clips 21, on a rocker 28 pivoted on a horizontal stud 23 and having a pointed rocker arm 39 depending therefrom for riding engagement, in a manner presently explained, with the outer side of the flange I6 to intermittently hold the mercury switch 25 rocked into open position.

A coil spring 3|, at one side of the stud 29, has its ends suitably connected to the rocker 28 and to a fixed stud 32 to normally rock the mercury switch 25 into closed position. Any suitable arrangement of leads 33, 34 may be provided for connecting the mercury switch 25 in circuit with the motor 2.

A tappet crank pin 35 on the spur gear 9 is arranged to wipingly engage a lateral lug 39 on the rocker 28, momentarily, to rock the mercury switch 25 into open position.

A fixed stop pin 3'! for the rocker 28 limits rocking movement of the mercury switch 25 into closed position.

Referring now to the operation of the invention, the shaft l3 and the switch controlling member l rotate counterclockwise, as viewed in Figures 2, 4 and 6 into a full cycle position in which the gap 24 is brought opposite the rocker arm 30. At this point, the rocker arm 30, under the influence of the coil spring 3|, swings and passes through the gap 24 into said member I5, as shown in broken lines in Figure 4, and upon further rotation of said member I5 wi es along the edge of the cam disk I9 and snaps into an edge notch 38 in the cam disk l9. During this operation of the rocker arm 39, the mercury switch 25 rocks in one direction, 1. e., counterclockwise as viewed in Figures 1, 3 and 5 into closed position as shown in Figure 3. As will be seen, when the rocker arm 30 snaps into the notch 38, the mercury switch 25 assumes closing position with a snap action which speeds its closing in a manner to obviate arcing in the mercury tube 26. As the switch controlling member I5 continues to rotate, the disked cam E9 is revolved away from the rocker arm 35 until said member I5 has rotated substantially 325 degrees, at which point the disked cam i9 is revolved into reengagement with the rocker arm 30 as shown in Figure 6. During the interim, the motor 2 has been energized to drive the power transmitting shaft 3 and the spur gear 9 counterclockwise as viewed in Figures 1, 3 and 5.

As the spur gear 9 and shaft 3 near full cycle position, and at substantially the point of reengagement of the disked cam I9 with the rocker arm 30, or slightly before, the tappet crank pin 35 wipingly engages the lug 36, as shown in dotted lines in Figure 5, and rides oif said lug in the full cycle position of the spur gear 9 and shaft 3, as shown in Figure 3. In the interim, said pin rocks the mercury switch 25, in opposition to the coil spring 3|, into open position, as shown in Figure 1. This rocks the rocker arm 30 out of the switch controlling member I5 across the flange I6 in wiping engagement therewith, said flange I6 flexing downwardly under engagement of said rocker arm therewith to permit said arm to rock out of said member I5.

As soon as the rocker arm 30 is thus rocked out of the switch controlling member l5, it rides against the outer side of the flange I6, as shown in Figures 1 and 2 and on the edge of the disk 4 cam I9 until the gap 24 is again presented opposite the rocker arm 30.

In case the shaft I3 is reversed, by incorrect operation, the disk cam I9 will prevent the rocker arm 30 from passing through the gap 24 into the switch controlling member I5 and thereby prevent the mercury switch 25 from assuming closed position. In case of failure of the motor drive I, with the tappet crank pin 35 disengaged from the lug 36, continued rotation of the switch controlling member 55 past the point of reengagement of the rocker arm 39 with the disk cam IE! will revolve said cam against said arm and cam said arm out of said member IE to open the mercury switch 25 and break circuit to the motor 2. The edge of the disk cam {9 extending from the gap 24 to the notch 38 serves to guide the rocker arm 30 through said gap and for snap action engagement with said notch 33, under the influence of the coil spring IN.

The foregoing will, it is believed, sufflce to impart a clear understanding of my invention, without further explanation.

Manifestly, the invention, as described, is susceptible of modification, without departing from the inventive concept, and right is herein reserved to such modifications as fall within the scope of the appended claims.

Having described the invention, what is claimed as new is:

1. A pivotally mounted switch rockable in opposite directions into open and closed positions, respectively, and spring tensioned for rocking into one position, a driven rotary dished member with a circumferential resilient flexible flange, a holding rocker arm on said switch for riding against the outer side of said flange to hold said switch in its other position under tension, said flange having a gap therein for passing said arm therethrough into said member to release said switch for rocking under tension into said one position, and driven means for rocking said switch into its other position and said arm out of said member past said flange in wiping engagement therewith to again ride the outer side of said flange.

2. A pivotally mounted switch rockable in opposite directions into open and closed positions, respectively, and spring tensioned for rocking into one position, a driven rotary dished member with a circumferential resilient flexible flange, a holding rocker arm on said switch for riding against the outer side of said flange to hold said switch in its other position under tension, said flange having a gap therein for passing said arm therethrough into said member to release said switch for rocking under tension into said one position, and driven means for rocking said switch into its other position and said arm out of said member past said flange in wiping engagement therewith to again ride the outer side of said flange, said means comprising a rotary element for wipingly engaging said switch momentarily to rock the same. 4

3. A pivotally mounted switch rockable in opposite directions into open and closed positions, respectively, and spring tensioned for rocking into one position, a driven rotary dished member with a circumferential resilient flexible flange, a holding rocker arm on said switch for riding against the outer side of said flange to hold said switch in its other position under tension, said flange having a gap therein for passing said arm therethrough into said member to release said switch for rocking under tension into said one position, and driven means for rocking said switch into its other position and said arm out of said member past said flange in wiping engagement therewith to again ride the outer side of said flange, said means comprising a rotary element for wipingly engaging said switch momentarily to drop the same and rotating faster than said member.

4. A pivotally mounted switch rockable in opposite directions into open and closed positions, respectively, and spring tensioned for rocking into one position, a driven rotary dished member with a circumferential resilient flexible flange, a holding rocker arm on said switch for riding against the outer side of said flange to hold said switch in its other position under tension, said flange having a gap therein for passing said arm therethrough into said member to release said switch for rocking under tension into said one position, driven means for rocking said switch into its other position and said arm out of said member past said flange in wiping engagement therewith to again ride the outer side of said flange, and a cam disk in said member for camming said arm out of said member past said flange in the event of failure of said driven means.

5. A pivotally mounted switch rockable in opposite directions into open and closed positions, respectively, and spring tensioned for rocking into one position, a driven rotary dished member with a circumferential resilient flexible flange, a holding rocker arm on said switch for riding against the outer side of said flange to hold said switch in its other position under tension, said flange having a gap therein for passing said arm therethrough into said member to release said switch for rocking under tension into said one position, and driven means for roclnng said switch into its other position and said arm out of said member past said flange in wiping engagement therewith to again ride the outer side of said flange, said member having a disk cam therein against which said arm rides in passing through said gap to guide said arm through the gap.

6. A pivotally mounted switch rockable in opposite directions into open and closed positions, respectively, and spring tensioned for rocking into one position, a driven rotary dished member with a circumferential resilient flexible flange, a holding rocker arm on said switch for riding against the outer side of said flange to hold said switch in its other position under tension, said flange having a gap therein for passing said arm therethrough into said member to release said switch for rocking under tension into said one position, and driven means for rocking said switch into its other position and said arm out of said member past said flange in wiping engagement therewith to again ride the outer side of said flange, said member having a disk cam therein against which said arm rides in passing through said gap to guide said arm through the gap, said disk cam having an edge notch within said member for snap action seating of said arm therein to speed rocking of said switch into its other position.

MARION F. MAURER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,032,826 Hamilton July 16, 1912 1,361,966 Colby Dec. 14, 1920 2,217,573 Terrell Oct. 8, 1940 2,251,385 Wade et a1 Aug. 5, 1941 

